Receive the latest movies updates in your inbox

When it comes to getting into character, Shia LaBeouf's dove right in for his new role in The Necessary Death of Charlie Countryman, an indie mob movie he just finished shooting.

"There's a way to do an acid trip like Harold & Kumar, and there's a way to be on acid," LaBeouf told USA Today in an interview. "What I know of acting, Sean Penn actually strapped up to that [electric] chair in Dead Man Walking. These are the guys that I look up to."

Shia, 26, plays the title character in Charlie Countryman, about a man who falls for a woman who's claimed by a violent crime boss. The flick, directed by Fredrik Bond, costars Harry Potter's Rupert Grint, Evan Rachel Wood and Mads Mikkelsen and is slated to premiere at next January's Sundance Film Festival.

The role is yet another that takes LaBeouf away from the blockbuster fare he's become known for such as Transformers and the fourth Indiana Jones and into more serious acting terrain. And Shia's met that challenge head-on with the aim of inhabiting the characters he's played.

At the premiere of Lawless, his new Depression-era drama about a family of bootleggers that just hit theaters, LaBeouf told E! News last week that he went so far as to sample real moonshine in order to understand how his character, Jack Bondurant, might act when hallucinating on the homemade liquor. He also further transformed himself by packing on 40 pounds so he could match the beefier look of his costars, Tom Hardy and Jason Clarke, who play his brothers in the film.

The actor has made his share of mistakes in his Hollywood career--like the brouhaha he caused when he said Steven Spielberg "dropped the ball" on Indiana Jones and the Kingdom of the Crystal Skull, a comment which Shia says he now regrets as it temporarily ruptured his relationship with the famed director. But LaBeouf told Parade in its latest issue that he's "learning."

"I'm more comfortable with myself, and I'm calming down," he said, particularly now that he's devoting himself to more grown-up roles in smaller, more challenging indie films. "I think most twentysomething men go through similar struggles and start seeing what boundaries and what rules are. It's about pushing limits and trying to find yourself. I've never been able to learn from other people's mistakes--I'm not that smart--so I usually learn by trial by fire."

Next month LaBeouf starts shooting Lars von Trier's erotic drama Nymphomaniac. He implied to MTV News that not only will he be doing all the sex scenes in the movie "for real," but he admitted being "terrified" to work with the Danish helmer.